A visit to the Churchill War Rooms, London

• 9 things you (probably) didn’t know about Winston Churchill
• Churchill: The ‘cry-baby’ war hero

In the summer of 1938, as the threat of war crept closer, a decision was taken to create a temporary government centre for emergency usage. That place turned out to be the basement of the New Public Offices (now the Treasury) which was specially adapted for their new role as functional war rooms, with quick access for senior military figures and safety provisions such as sandbags and solid wooden doors.

It was hoped that by keeping the government’s emergency base in London itself would reassure civilians that leaders had remained in the city during a crisis, rather than abandoning them for safety elsewhere.

The rooms became operational just days before Adolf Hitler invaded Poland on 1 September 1939. Two days later, Britain declared war on Germany.

• Listen | The historian and author Andrew Roberts discusses his new biography of Winston Churchill revealing insights arising from his research and tackling some of the biggest debates around Britain’s wartime prime minister

Gone to ground

Neville Chamberlain used the facility just once, but it left a much greater impression on his successor, Winston Churchill. On entering for the first time as prime minister, in May 1940, Churchill is said to have declared: “This is a room from which I will direct the war.

The War Cabinet met here 115 times during World War II, mainly during the Blitz and, later, V-weapon attacks. In October 1940, Blitz fear led to the complex being reinforced with slabs of concrete up to three metres thick, providing some peace of mind, but even then the complex was in danger. Any bomb larger than 227kg would have been powerful enough to destroy it.

Subterranean living could be difficult – staff had to stand under sun lamps to get a daily dose of ‘sunlight’, and one woman nearly went blind after she forgot to wear goggles for a session. Weather indicator boards were used to keep those underground apprised of the weather outside, with ‘windy’ often used during heavy raids.

The Map Room – the bunker’s intelligence hub – was in use 24 hours a day, staffed by members of the Royal Navy, Army and RAF. Daily intelligence was analysed and delivered from here to the King and the Prime Minister. But intel of a more sensitive nature was dealt with in what appeared to be Churchill’s personal toilet.

• Churchill and D-Day: did the prime minister oppose the Normandy landings?
• Did Churchill’s postwar speeches save the world?

The perfidious privy’s lavatory style lock was a delicate ruse – behind the otherwise unsecured door was actually a small storeroom, from which Churchill could speak to US President Franklin D Roosevelt in private, via a secure radio-telephone link. Their first call in what was officially the Transatlantic Telephone Room took place on 15 July 1943. Accommodation was also created for Churchill and his family and the prime minister made four broadcasts from his underground bedroom.

After the war, the rooms were left exactly as they were. As early as 1948, the question of public access to these historic rooms was raised, but the confidentiality of the work carried out there caused government concern. This didn’t stop visitation requests pouring in, so occasionally by request, small groups were allowed in. The War Rooms were finally opened to the public in 1984.

Highlights of a visit include Churchill’s Cabinet Room chair, gouged with anxious scratch marks, and the phone he used to speak to the US president.

This article is taken from the November 2019 issue of BBC History Revealed.